/*
 * The contents of this file are subject to the terms of the Common Development and
 * Distribution License (the License). You may not use this file except in compliance with the
 * License.
 *
 * You can obtain a copy of the License at legal/CDDLv1.0.txt. See the License for the
 * specific language governing permission and limitations under the License.
 *
 * When distributing Covered Software, include this CDDL Header Notice in each file and include
 * the License file at legal/CDDLv1.0.txt. If applicable, add the following below the CDDL
 * Header, with the fields enclosed by brackets [] replaced by your own identifying
 * information: "Portions Copyright [year] [name of copyright owner]".
 *
 * Copyright 2008 Sun Microsystems, Inc.
 * Portions Copyright 2013-2016 ForgeRock AS.
 */
package org.forgerock.opendj.server.core;

import org.forgerock.opendj.ldap.LdapPromise;
import org.forgerock.opendj.ldap.LdapResultHandler;

/**
 * A data provider which supports backup and restore functionality.
 * <p>
 * TODO: do we need supportsRestore?
 * <p>
 * TODO: do we need removeBackup?
 * <p>
 * TODO: is there any boiler plate code that abstracted in order to make implementation simpler?
 * E.g. initialization, crypto.
 * <p>
 * FIXME: the async APIs used below are a bad fit. We do not want to return an
 * {@link org.forgerock.opendj.ldap.LdapException}. We really need a more generic promises API.
 */
public interface ArchivableDataProvider {

    /**
     * Creates a backup of the contents of this data provider in a form that may
     * be restored at a later date if necessary. This method should only be
     * called if {@code supportsBackup} returns {@code true}.
     * <p>
     * Note that the server will not explicitly initialize this data provider
     * before calling this method.
     *
     * @param backupConfig
     *            The configuration to use when performing the backup.
     * @param handler
     *            A handler which will be notified when the backup completes.
     * @return A promise representing the completion of the backup.
     */
    LdapPromise<Void> createBackup(BackupConfig backupConfig, LdapResultHandler<Void> handler);

    /**
     * Returns the ID of this data provider.
     *
     * @return The ID of this data provider.
     */
    DataProviderID getDataProviderID();

    /**
     * Restores a backup of the contents of this data provider.
     * <p>
     * Note that the server will not explicitly initialize this data provider
     * before calling this method.
     *
     * @param restoreConfig
     *            The configuration to use when performing the restore.
     * @param handler
     *            A handler which will be notified when the restore completes.
     * @return A promise representing the completion of the restore.
     */
    LdapPromise<Void> restoreBackup(RestoreConfig restoreConfig, LdapResultHandler<Void> handler);

    /**
     * Indicates whether this data provider provides a mechanism to perform a
     * backup of its contents in a form that can be restored later, based on the
     * provided configuration.
     *
     * @param backupConfig
     *            The configuration of the backup for which to make the
     *            determination.
     * @param unsupportedReason
     *            A buffer to which a message can be appended explaining why the
     *            requested backup is not supported.
     * @return {@code true} if this data provider provides a mechanism for
     *         performing backups with the provided configuration, or
     *         {@code false} if not.
     */
    boolean supportsBackup(BackupConfig backupConfig, StringBuilder unsupportedReason);
}
